setAttributeNS adds a new attribute or changes the value of an attribute with the given namespace and name.


element.setAttributeNS(namespace, name, value)
  • namespace is a string specifying the namespace of the attribute.
  • name is a string identifying the attribute by its qualified name; that is, a namespace prefix followed by a colon followed by a local name.
  • value is the desired string value of the new attribute.


let d = document.getElementById('d1');
d.setAttributeNS('http://www.mozilla.org/ns/specialspace', 'spec:align', 'center');


DOM methods dealing with element's attributes:

Not namespace-aware, most commonly used methods Namespace-aware variants (DOM Level 2) DOM Level 1 methods for dealing with Attr nodes directly (seldom used) DOM Level 2 namespace-aware methods for dealing with Attr nodes directly (seldom used)
setAttribute (DOM 1) setAttributeNS setAttributeNode setAttributeNodeNS
getAttribute (DOM 1) getAttributeNS getAttributeNode getAttributeNodeNS
hasAttribute (DOM 2) hasAttributeNS - -
removeAttribute (DOM 1) removeAttributeNS removeAttributeNode -

setAttributeNS is the only method for namespaced attributes which expects the fully qualified name, i.e. "namespace:localname".


DOM Standard (DOM)
# ref-for-dom-element-setattributens①

Browser compatibility

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